We are introduced a software for post processing the singlebeam hydrographic survey datas with low cost. Our software can be interpolated the water level in post-processing hydrographic survey combining with DGPS receivers, calculated the coordinate and elevation of the river/sea bottom by GPS RTK technology, supported for processing in ?Base-Rover? and Precise Point Positioning (PPP) mode, ? The reliability of HydroTools software is also approved when comparing with the results from the famous hydrographic survey software Hypack Max (USA).